<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        let persons = [
    {
        username:'张飞',
        sex:'男',
        salary:50000 
    },
    {
        username:'关羽',
        sex:'男',
        salary:60000
    }
]
let arr=JSON.parse(JSON.stringify(persons));
arr[0].salary+=2000;
arr[1].salary+=2000;
console.log(persons);
console.log(arr);
    </script>
</body>
</html>